JP2007046668A - Valve structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve structure which prevents delay in returning to the position to abut on a valve body of a leaf valve. <P>SOLUTION: This valve structure is provided with: the valve body 1 having a port 2; a rod 5 protruding from an axis part of the valve body 1; the annular leaf valve 10 having an inner peripheral side to which the rod 5 is inserted and placed on the valve body 1 so as to close the port 2; an energizing means 15 for energizing the leaf valve 10 to the direction of closing the port 2; and a stopper 25 formed to be in a bottomed cylindrical shape and arranged to have an aperture facing the leaf valve 10 side so that the leaf valve 10 resists the energizing force of the energizing means 15 at the aperture, and that a retreat amount retreating from the valve body 1 is regulated. In this case, the leaf valve 10 is constituted by at least one of annular disks 11 and 12, and at least an outside diameter of the annular disk 12 confronting the aperture of the stopper 25 is larger than the outside diameter of the aperture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improved valve structure.

  Conventionally, in this type of valve structure, as shown in FIG. 2, there is a leaf valve L1 that is bent at the outer periphery, a leaf spring S1 that biases the back surface of the leaf valve L1, and a deflection amount of the leaf valve L1. One having a bottom cylindrical stopper St1 is known (see, for example, Patent Document 1).

  In this valve structure, as shown in the drawing, when the piston speed when the piston P1 moves downward is in the low speed region, the outer peripheral side of the leaf valve L1 does not come into contact with the stopper St1, but the piston speed is in the middle high speed region. When the pressure reaches, the pressure of the hydraulic oil passing through the port Po1 acts on the leaf valve L1, and the leaf valve L1 is greatly deflected against the urging force of the leaf spring S1 to contact the lower end opening of the stopper St1.

  As described above, in the valve structure, in order to prevent the gap between the leaf valve L1 and the piston P1 that is generated when the leaf valve L1 is bent from being excessively large, the stopper St1 is used for the leaf valve. The amount of retreat of L1 is regulated.

  The stopper St1 regulates the retraction amount of the leaf valve L1 by bringing the leaf valve L1 into contact with the lower end portion of the stopper St1, but the leaf valve L1 comes into contact with the lower end opening portion so that the inside of the stopper St1 is maintained. It will be blocked.

  In this state, when the moving direction of the piston P1 is reversed and starts to move upward in the figure from the piston P1, the force pushed up by the hydraulic oil disappears so that the leaf valve L1 is in a position where the port Po1 closes. However, as described above, the inside of the stopper St1 is closed and the piston P1 is moved upward, so that the pressure outside the stopper St1 is increased, and the leaf valve L1 is placed at the lower end of the stopper St1 for a while. There is a possibility that a delay may occur in the return to the position where the port Po1 of the leaf valve L1 is closed due to the contact state.

  Therefore, in order to avoid such a situation, the stopper St1 is provided with a through hole h1 that communicates the inside and outside of the stopper St1, so that the inside of the stopper St1 is not blocked by the leaf valve L1. .

  By the way, in particular, in the above valve structure in which the leaf valve is separated from the valve seat by fixing and supporting the inner periphery of the leaf valve and bending the outer periphery, the damping force in the middle and high speed regions becomes high, and the riding in the vehicle is increased. As shown in FIG. 3, the inner periphery of the leaf valve L2 is not fixedly supported, and the inner periphery of the leaf valve L2 is fixed to the piston rod R2 or the piston rod R2, as shown in FIG. A valve structure is also known in which the back surface of the leaf valve L2 is urged by a spring S2 in sliding contact with the outer periphery of a spacer G2 disposed on the outer periphery of the spacer (see, for example, Patent Document 1).

  In this valve structure, as shown in the figure, when the piston speed when the piston P2 moves downward is in the low speed region, the outer peripheral side of the leaf valve L2 bends with the urging position of the spring S as a fulcrum. Exhibits substantially the same damping characteristics as the valve structure that is fixedly supported, and when the piston speed reaches the middle-high speed range, the pressure of the hydraulic oil passing through the port Po2 acts on the leaf valve L2, and the spring S2 is attached. Since the entire leaf valve L2 is lifted and retracted from the piston P2 in the axial direction against the force, the flow passage area is larger than the valve structure in which the inner periphery is fixedly supported, and the damping force is excessive. The ride comfort in the vehicle can be improved.

However, in the valve structure of FIG. 3, since there is no stopper, it is not possible to regulate the gap generated between the leaf valve L2 and the piston P1. Therefore, it is possible to propose to apply the stopper St1 in the valve structure of FIG. 2 to the valve structure of FIG.
Japanese Patent Laid-Open No. 9-291196 (FIG. 1)

  However, the stopper St1 in the valve structure of FIG. 2 is not fixedly supported on the inner peripheral side of the leaf valve L2 as shown in FIG. 3, and the inner periphery of the leaf valve L2 is connected to the outer periphery of the piston rod R2 or the piston rod R2. There is a possibility that it is pointed out that there are the following problems when applied to a valve structure in which the outer periphery of the spacer G2 is slidably contacted and the back surface of the leaf valve L2 is urged by the spring S2.

  This is because, in the valve structure shown in FIG. 3, when the piston speed when the piston P2 moves downward in the drawing reaches the middle-high speed region, the leaf valve L2 moves backward from the piston P2 in the axial direction. When the piston P2 is lifted and the moving direction of the piston P2 is reversed and starts to move upward in the figure, the force that has been pushing up the leaf valve L2 by the hydraulic oil until then decreases or disappears, so the leaf valve L2 contacts the piston P2. At this time, the lifted leaf valve L2 sticks to the opening at the lower end of the stopper St1, and the leaf valve can be maintained even if the stopper St1 is kept in communication through the through hole h1. There is a possibility that a delay may occur in the return to the position where L2 contacts the piston P2.

  In addition, a proposal can be made to prevent the sticking by providing a notch in the lower end opening of the stopper St1 and making it a through hole to reduce the contact area between the leaf valve L2 and the lower end opening. If the contact between the lower end opening and the leaf valve L2 is repeated for many years, the lower end opening is flattened, and sticking between the stopper St1 and the leaf valve L2 cannot be prevented over a long period of time. There is sex.

  When a delay occurs in the return of the leaf valve L2, it takes an extra time until the leaf valve L2 comes into contact with the piston P2 and closes the port Po2, and the time until the valve P2 is closed The hydraulic oil will freely pass through the port from the upper side to the lower side.

  Then, during the time until the closing, the difference between the pressures of the upper and lower working chambers partitioned by the piston P2 does not occur, so that the shock absorber can no longer generate a sufficient damping force. .

  Therefore, the present invention was devised to improve the above-mentioned problems, and an object of the present invention is to provide a valve structure that does not cause a delay in returning the leaf valve to a position where it abuts on the valve body. That is.

  In order to solve the above-described object, the problem-solving means in the present invention includes a valve body in which a port is formed, a rod protruding from an axial center portion of the valve body, and the rod is inserted on the inner peripheral side. An annular leaf valve that is stacked on the valve body and closes the port, a biasing means that biases the leaf valve in the direction of closing the port, and a bottomed cylindrical opening that faces the leaf valve In the valve structure provided with a stopper that restricts the amount of retreat of the leaf valve from the valve body against the urging force of the urging means at the opening, the leaf valve has one or a plurality of annular shapes. The outer diameter of at least the annular plate facing the opening of the stopper is made larger than the outer diameter of the opening.

  According to the valve structure of the present invention, since the outer diameter of the annular plate facing the opening of the stopper is larger than the outer diameter of the opening of the stopper, even if the leaf valve sticks to the opening of the stopper, Since the leaf valve can be surely removed from the stopper assuredly, there is no delay in returning to the position where the leaf valve contacts the valve body.

  In addition, since there is no delay in the return to the position where the leaf valve contacts the valve body, the time until the leaf valve contacts the valve body and closes the port is shortened. The response of the generation of damping force can be improved.

  Furthermore, in the aspect where the moving direction of the valve body is reversed, that is, in the case of this embodiment, the leaf valve can quickly close the port with good responsiveness when the shock absorber is switched from the expansion stroke to the compression stroke. Therefore, the time for the hydraulic oil to freely pass through the port can be shortened, and a sufficient damping force can be generated in the shock absorber from the beginning of the compression stroke.

  The valve structure of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a part of a piston portion of a shock absorber in which a valve structure according to an embodiment is embodied.

  As shown in FIG. 1, the valve structure in one embodiment is embodied as an extension-side damping valve of a piston portion of a shock absorber, and includes a piston 1 as a valve body in which a port 2 is formed, and a shaft of the piston 1. A rod 5 protruding from the center, an annular leaf valve 10 that is stacked on the piston 1 and closes the port 2 when the rod 5 is inserted on the inner peripheral side, and the leaf valve in a direction to close the port 2 And a spring member 15 as an urging means for urging 10 and a bottomed cylindrical shape, the opening is disposed toward the leaf valve 10 side, and the amount of retraction of the leaf valve 10 from the piston 1 is reduced by the opening. It comprises a stopper 25 for regulating.

  On the other hand, a shock absorber in which this valve structure is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 40 and a head member (not shown) that seals the upper end of the cylinder 40. ), The rod 5 slidably passing through the head member (not shown), the piston 1 provided at the end of the rod 5, the upper chamber 41 defined by the piston 1 in the cylinder 40, and the lower The chamber 42 and a sealing member (not shown) for sealing the lower end of the cylinder 40 are provided, and the cylinder 40 is filled with hydraulic oil.

  When the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the valve structure is operated via the port 2 from the lower chamber 42 to the upper chamber 41 when the pressure in the lower chamber 42 increases. When the oil moves, the leaf valve 10 provides resistance to the movement of the hydraulic oil to cause a predetermined pressure loss, thereby functioning as a damping force generating element that generates a predetermined damping force in the shock absorber.

  Hereinafter, the valve structure will be described in detail. The piston 1 serving as a valve body is formed in a disc shape having an insertion hole 1a into which a shock absorber rod 5 is inserted in the shaft center portion, and communicates with the port 2 and the port 2. And a valve seat 4 formed on the outer peripheral side of the window 3 serving as an outlet end of the port 2.

  A rod 5 is inserted into the insertion hole 1a of the piston 1, and the tip of the rod 5 is protruded upward of the piston 1 in FIG. Although not shown, the outer diameter of the tip of the rod 5 is set to be smaller than the outer diameter of the lower side (not shown), and a step portion (not shown) is formed at a portion where the outer diameters of the lower side and the tip are different. ing.

  The rod 1 is inserted into the spacer 6 and the stopper 25, and the piston nut 30 is screwed onto the rod 5 from above the spacer 6 and the stopper 25 in FIG. Are fixed to the rod 5 by being sandwiched between the step portion and the spacer 6.

  Since the spacer 6 is provided for the purpose of fixing the piston 1 to the rod 5, the spacer 6 can be omitted when the piston 1 can be fixed to the rod 5 by another means.

  Further, in the present embodiment, the insertion hole 1a is provided in the piston 1 so that the tip of the rod 5 is inserted, and the rod 5 is projected. However, the rod integral with the piston 1 serving as the valve body is connected to the piston. You may make it provide in the axial center part of 1. FIG.

  Subsequently, the stopper 25 includes a plate 26 that is clamped and fixed to the tip of the rod 5 by the upper end of the spacer 6 and the piston nut 30, and a cylindrical body 27 that is suspended from the outer periphery of the plate 26 toward the leaf valve 10. And a through hole 26 a provided in the plate 26, and is configured in a bottomed cylindrical shape, and an insertion hole 26 b into which the rod 5 is inserted is provided in the axial center portion of the plate 26. The shape of the through hole 26a may be any shape, and the number thereof is also arbitrary.

  The stopper 25 is attached to the rod 5 with the lower end opening in FIG. 1 of the cylinder 27 serving as the opening facing the piston 1 side. The cylindrical body 27 may have a shape other than the cylindrical shape. Further, when the biasing means described later is a coil spring, the plate 26 is provided with a step portion for preventing the eccentricity of the coil spring, or the cylindrical body 27 is shaped so that the inner diameter at the joint portion between the cylindrical body 27 and the plate 26 is the coil spring. It is possible to prevent the eccentricity of the coil spring as a conical shape that expands toward the lower end opening and adjusts to the outer diameter of the coil spring.

  In turn, the annular leaf valve 10 is composed of a plurality of annular plates 11, and the annular plates 11, 12 positioned at the lowermost position in FIG. The spacers 6 are stacked and inserted on the inner peripheral side of the leaf valve 10. Then, the outer diameter of the annular plate 12 stacked in the uppermost stage in FIG. 1 among the annular plates 11 and 12 of the leaf valve 10, that is, the lowermost end of the cylindrical body 27 that is the opening of the stopper 25 is faced. The outer diameter of the annular plate 12 is larger than the outer diameter of the lower end opening of the cylinder 27 that is the opening of the stopper 25. Although the outer diameter of the annular plate 11 is made smaller than the outer diameter of the annular plate 12 in the drawing, it may be the same diameter or a larger diameter.

  Further, a spring member 15 as an urging means is interposed between the plate 26 of the stopper 25 and the leaf valve 10, and the leaf valve 10 receives the urging force of the spring member 15. Yes.

  That is, the leaf valve 10 is always urged in the direction of closing the port 2 by the spring member 15, and when the difference between the pressure in the lower chamber 42 and the pressure in the upper chamber 41 becomes a predetermined value or more, The spring member 15 is compressed against the force, and the entire leaf valve 10 is retracted in the axial direction from the piston 1, that is, lifted upward in FIG. Then, the leaf valve 10 is finally retracted until it comes into contact with the lower end opening in FIG. 1 of the cylindrical body 27 of the stopper 25 described above, and the stopper 25 regulates the retraction amount of the leaf valve 10. Acts like

  In the above description, the urging means is a spring member 15 that is a coil spring in the figure, but a predetermined urging force may be applied to the leaf valve 10, and this may be applied to, for example, a disc spring or a leaf spring. Or an elastic body such as rubber.

  Note that the number of the annular plates 11 and 12 in the leaf valve 10 may be arbitrary depending on the damping characteristics realized by the valve structure. For example, the leaf valve 10 may be configured by one piece. In the case of a single annular plate, the outer diameter of the annular plate may be larger than the outer diameter of the lower end opening of the cylinder 27 that is the opening of the stopper 25.

  Next, the operation of the valve structure will be described. As described above, when the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the pressure in the lower chamber 42 increases, and the hydraulic oil in the lower chamber 42 increases. It tries to move into the upper chamber 41 through the port 2.

  When the piston speed is in the low speed region, the leaf valve 10 is urged by the spring member 15 so as to close the port 2, so that the outer peripheral edge of the leaf valve 10 is the spring member 15 of the leaf valve 10. The hydraulic oil passes through a gap between the leaf valve 10 and the valve seat 4, which is formed by the leaf valve 10 being separated from the valve seat 4.

  On the other hand, when the speed of the piston 1 is high and the difference between the pressure in the lower chamber 42 and the pressure in the upper chamber 41 exceeds a predetermined value, the force that pushes the leaf valve 10 upward in FIG. The urging force of the spring member 15 is overcome, and the entire leaf valve 10 is retreated in the axial direction from the piston 1, that is, moved upward in FIG.

  When the leaf valve 10 comes into contact with the lower end opening of the cylinder 27, which is the opening of the stopper 25, the leaf valve 10 is further retracted away from the piston 1 along the axis by the stopper 25. As a result, the retraction amount of the leaf valve 10 is regulated.

  Therefore, the stopper 25 can adjust the maximum gap formed between the leaf valve 10 and the piston 1 and prevent the damping force from becoming excessively large due to the maximum gap becoming larger than necessary. Is possible.

  Then, when the moving direction of the piston 1 turns upward in FIG. 1 from this state, the hydraulic oil moves from the inside of the upper chamber 41 to the inside of the lower chamber 42. Since the outer diameter of the annular plate 12 facing the lower end opening of the cylindrical body 27 is larger than the outer diameter of the cylindrical body 27, the outer peripheral portion that protrudes from the cylindrical body 27 of the annular plate 12 obstructs the flow of the hydraulic oil. Works.

  That is, the outer peripheral portion of the annular plate 12 that protrudes from the cylindrical body 27 receives a force downward in FIG. 1 due to the flow of the hydraulic oil, so that the leaf valve is provided at the lower end opening of the cylindrical body 27 of the stopper 25. 10, the opening of the stopper 25 is not only affected by the pressure of the hydraulic oil flowing into the stopper 25 from the through hole 26 a and the biasing force of the spring member 15 but also by the flow of the hydraulic oil. The annular plate 12 can be quickly detached from the lower end opening of the cylindrical body 27.

  Therefore, in the valve structure according to this embodiment, the outer diameter of the annular plate 12 facing the opening of the stopper 25 is made larger than the outer diameter of the lower end opening of the cylinder 27 that is the opening of the stopper 25. Even if the leaf valve 10 of the leaf valve 10 sticks to the lower end opening of the cylinder 27, which is the opening of the stopper 25, the leaf valve 10 can be surely removed from the stopper 25 immediately. There is no delay in the return to the position where the leaf valve 10 contacts the piston 1.

  Further, since there is no delay in returning to the position where the leaf valve 10 contacts the piston 1, the time until the leaf valve 10 contacts the piston 1 and closes the port 2 is shortened. Responsiveness of the damping force generation of the shock absorber can be improved.

  Further, in the aspect where the moving direction of the piston 1 is reversed, that is, in the case of this embodiment, the leaf valve 10 quickly closes the port 2 with good responsiveness when the shock absorber is switched from the expansion stroke to the compression stroke. Therefore, the time for the hydraulic oil to freely pass from the upper chamber 41 to the lower chamber 42 via the port 2 can be shortened, and a sufficient damping force is generated in the shock absorber from the beginning of the compression stroke. It can be done.

  This is the end of the description of the embodiment of the valve structure, but the valve structure of the present invention can be embodied in the compression side damping valve of the piston portion of the shock absorber, or in the base valve portion. Of course, the present invention can be applied to a damping valve that functions as a damping force generating element that generates a damping force.

 It should be noted that the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view in a part of piston part of the shock absorber in which the valve structure in one embodiment was embodied. It is a longitudinal cross-sectional view of the conventional valve structure. It is a longitudinal cross-sectional view of the conventional valve structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 1a, 26b which is a valve body Insertion hole 2 Port 3 Window 4 Valve seat 5 Rod 6 Spacer 10 Leaf valve 11, 12 Annular plate 15 Spring member 25 as urging means Stopper 26 Plate 26a Through hole 27 Cylindrical body 30 Piston nut 40 Cylinder 41 Upper chamber 42 Lower chamber

Claims (2)

A valve body in which a port is formed, a rod protruding from the axial center of the valve body, an annular leaf valve that is stacked on the valve body and closes the port, and the port is inserted into the inner peripheral side; An urging means for urging the leaf valve in a closing direction, and an opening formed in a bottomed tube shape with the opening facing the leaf valve, and the leaf valve is urged by the urging means at the opening. In the valve structure provided with a stopper that regulates the amount of retreat from the valve body against the leaf valve, the leaf valve is composed of one or a plurality of annular plates, and at least the annular plate facing the opening of the stopper A valve structure characterized in that the outer diameter of the valve is larger than the outer diameter of the opening. The valve structure according to claim 1, wherein the stopper includes a through hole that communicates the inside and outside of the stopper.

Images